DURBAN 2011:AFTER ANOTHER year of extreme weather events, including October's flooding in the Dublin area, the UN's Intergovernmental Panel on Climate Change (IPCC) has warned global warming will cause even stronger storms, more heatwaves, droughts and wildfires unless steps are taken to curb the current trends.
Its latest report, Managing the Risks of Extreme Events and Disasters, released on November 18th, says scientists are "virtually certain" the world will have more extreme spells of heat, and fewer cold spells. Heatwaves could be as much as 5 degrees hotter by 2050 and even 9 degrees hotter by 2100.
If greenhouse gas emissions in the atmosphere continue rising inexorably, “it is likely that the frequency of hot days will increase by a factor of 10 in most regions of the world”, according to Thomas Stocker, co-chair of the IPCC working group. Likewise, heavy rainfall will occur more often, and tropical cyclones will become more intense.
By the end of this century, intense, heavy rainstorms that now typically happen only once every 20 years are likely to occur about twice a decade, according to the report. The most recent bizarre weather extreme – October’s snowstorm in the northeastern US – is typical of the damage climate scientists warn will occur more frequently.
Coastal communities, including those in major delta areas and on small islands, will be more exposed and vulnerable to the impacts of rising temperatures – especially in the developing world – and some locations are likely to become “increasingly marginal as places to live” as catastrophes take their toll on life and property.
“The report shows that if we do not stop the current steep rise in atmospheric levels of greenhouse gases, we will see much more warming and dramatic changes in extreme weather which are likely to overwhelm any attempts human populations might make to adapt to their impacts,” said Bob Ward of the London School of Economics (LSE).
“This expert review of the latest available scientific evidence clearly shows that climate change is already having an impact in many parts of the world on the frequency, severity and location of extreme weather events, such as heatwaves, droughts and flash floods,” said Ward, a director of the LSE’s Grantham Research Institute.
Unlike previous IPCC reports, the latest is prefaced by an almost anodyne and highly qualified “summary for policymakers” – as if the UN panel, which had been criticised for making errors, is kicking for touch. All of the risks are carefully calibrated in terms of their likelihood of happening, so nobody can say the scientists are being alarmist.
IPCC chairman Dr Rajendra Pachauri said the summary “underlines the complexity and the diversity of factors that are shaping human vulnerability to extremes – why, for some communities and countries, these can become disasters, whereas for others they can be less severe”, and how disaster risk management “may assist”.
Nonetheless, the report follows an extraordinary year of extremes, which has seen the US alone rack up a record 14 “billion-dollar disasters”. Altogether, these disasters are estimated to have caused $53 billion (€39.4 billion) in damage, putting 2011 in fifth place for most damages from billion-dollar weather disasters since records began.
The damage estimate in Connecticut alone from the unseasonal snowstorm that hit the northeast on October 29th has been put at $3 billion.
An incredible 32 inches (818mm) of snow was dumped on the area – by far the largest volume since a legendary snow hurricane in 1804. But the damage caused, including 22 deaths, was eclipsed by that of a tornado that hit Alabama last April, which (at $9 billion) was the most expensive US weather-related disaster of 2011.
Tornadoes, hurricanes and floods killed 675 people in the US, putting this year into fourth place since 1940 for most deaths due to severe storms, Weather Underground’s meteorology director Dr Jeff Masters said. In 2005, Hurricane Katrina accounted for most of that year’s 1,000 disaster-related deaths.
Masters, who was not involved in the IPCC study, said blistering heat from June to August this year set 2,703 daily high temperature records, compared with only 300 cold records during that period, making the summer “the hottest summer in the US since the Dust Bowl of 1936”. Texas, Arizona and New Mexico were particularly badly affected.
“In the US, this has been the weirdest weather year we’ve had for my 30 years, hands down. Certainly this October snowstorm fits in with it,” he said.
The US National Oceanic and Atmospheric Administration agrees 2011 has been one of the most extreme years on record.
“Extremes of precipitation are generally increasing because the planet is actually warming and more water is evaporating from the oceans,” according to Tom Karl, director of the agency’s national climatic data centre.
The US was not alone in experiencing extreme weather events this year. More than 600 people in Thailand lost their lives in the worst floods for more than half a century. In late October about a third of the country was under water, including the outskirts of Bangkok, and it took an almost super-human effort to prevent the city from being engulfed.
In September, torrential rain and floods paralysed Pakistan’s commercial capital, Karachi, and much of Sindh province for the second year running. Schools and markets were forced to close as villages were inundated by floods. More than five million people were affected by the flooding, which claimed at least 260 lives.
India was also hit by monsoon rain, with 2,600 villages across 19 districts in the eastern state of Orissa submerged, displacing more than a million people. In the Horn of Africa, the absence of rain for two consecutive seasons led to the worst drought in 60 years, threatening millions with starvation.
Meanwhile, summer sea ice in the Arctic was melting at its fastest rate since satellite observations began in 1972, reaching a new record minimum of 4.24 million sq km on September 8th, according to polar scientists from the University of Bremen. The previous one-day minimum was 4.27 million sq km on September 17th, 2007.
Temperatures in the Arctic have been increasing more than twice as fast as the global average, and this is having an impact on the extent of summer sea ice in the region. “The sea-ice retreat can no more be explained with the natural variability from one year to the next,” said Georg Heygster, head of Bremen’s Institute of Environmental Physics.
“It seems to be clear that this is a further consequence of the man-made global warming with global consequences,” Dr Heygster told the Guardian recently. “Climate models show that the reduction is related to the man-made global warming which, due to the albedo effect, is particularly pronounced in the Arctic.” The albedo effect relates to the reflecting power of any surface: whiter sea ice reflects more of the Sun’s heat into space than sea water. Thus, Arctic ice plays a critical role in regulating the climate by keeping the polar region cool. Its retreat is seen as further evidence of global warming.
This year, both the Northwest and Northeast passages through the Arctic were mostly free of ice, as they have been twice since 2008. Last August, the 74,000-tonne STI Heritage, a Panamax-class oil tanker, passed through the Northeast Passage from Murmansk to Thailand in just eight days, travelling at a speed of 14 knots.
If the trend continues, the Arctic could be largely free of summer sea ice within three decades – much sooner than the IPCC has forecast – and for the first time in 125,000 years. “This stunning loss of Arctic sea ice is yet another wake-up call that climate change is here now,” said Shaye Wolf of San Francisco’s Centre for Biological Diversity.
Deniers such as former Northern Ireland minister for the environment Sammy Wilson (DUP) need to sit up and take note. After the coldest summer here for two decades and fears this winter could be worse than last year, he claimed in a blog on September 14th last that “the world is getting cooler [and] global warming is clearly not occurring”.
But Prof John Sweeney of NUI Maynooth, who has contributed to IPCC reports, said last month’s floods in the Dublin area were consistent with climate computer models. “We can’t say this event is due to climate change, but the increase in frequency of intense rainfall events is on an upward curve.” he said.
Greenpeace climate policy co-ordinator Tove Maria Ryding said the latest IPCC report “brings home the inescapable fact: that climate change is not only fuelling extreme weather, it is causing an escalation in impacts both on humans and economies, most of which are increasingly being borne by the developing world”.
Ministers gathering in Durban must respond “by adopting a clear roadmap towards a science-based global agreement that will ensure all countries take action to dramatically reduce greenhouse gas emissions, and that financial and technical support is delivered to developing countries,” she said.
ROAD TO DURBAN KEY STAGES
1990:Negotiations get under way on what became the UN Framework Convention on Climate Change (UNFCCC).
1992: The convention is adopted at the Earth Summit in Rio de Janeiro, committing all parties to combat climate change.
1995:First Conference of the Parties (CoP) held in Berlin, chaired by Angela Merkel, then Germany's environment minister.
1997:CoP 3 in Kyoto adopts protocol committing developed countries to reduce their greenhouse gas emissions.
1998-2002:Successive CoPs wrangle about the rules for implementing the Kyoto Protocol, including emissions trading.
2005:Kyoto finally enters into force after Russia ratifies the protocol and runs from 2008 to 2012.
2007:CoP 13 in Bali launches an "action plan" to conclude negotiations on a successor to Kyoto in 2009.
2009:CoP 15 in Copenhagen - the biggest ever - fails to reach a binding agreement, leaving the future unclear.
2010:CoP 16 in Cancún rescues the process by agreeing to set up the Green Climate Fund and to protect forests.
2011:CoP 17 in Durban, which opens today, still has the unresolved issue of Kyoto's future on the table.
Tomorrow: The emissions challenge: How C02 levels are continuing to rise.
